One feature that is often missing from competitive games is one that allows you to get better. Playing a lot is one thing, certainly, but watching those better than you allows you to see where you are going wrong and allows you to look at areas where you could improve. Rocket league doesn’t have this; it had a few clips uploaded to YouTube of various good players doing good things (and several of bad players doing bad things) but no way of watching.
The most recent DLC has allowed a spectator mode but, again, it feels like a missed opportunity. The mode, which should allow you to watch any player or friend in the game, has limited itself to just being able to watch private matches of people you know. As no one plays private matches anyway, certainly none of the pro players who you would want to watch, the mode is complete missed opportunity.